I wonder if anyone who spotted coding errors in the printed book has checked to see if the same errors appear in the downloadable code?
(I am generally not very tolerant of coding errors in books. However, now that I have been through the process of writing a book, I can understand how it happens. You have endless iterations on your own, and eventually you give the text to the publisher. It's very easy to notice and fix something after that. You can either forget to provide the correction to the publisher, or the publisher can do a careless job of making a correction you tell them about. The same mechanics can slip problems past the technical reviewer. "Oh, right, here's the corrected version that I'm sending to the publisher. Try this one.")
So, anyhow, if they are corrected in the downloadable stuff, then it's at least sort of ok.
FWIW, I'm about 2/3 through this book and think it's an excellent "getting started" book for Arduino.